Currently, various types of wireless communication devices such a smart phone, a tablet PC, a PC and the like are developed.
Such wireless communication devices require a plurality of antennas for communicating across each frequency band because the wireless communication devices have wireless communication systems such as Long Term Evolution (LTE) (e.g., 800 MHz, 1.8 GHz, 2.1 GHz, 2.6 GHz), 3G (e.g., 1.8 GHz, 2.1 GHz), Worldwide Interoperability for Microwave Access (WiMAX) (e.g., 2.3 GHz, 3.3 GHz, 5.7 GHz), wireless Local Area Network (LAN) (e.g., 2.4 GHz), Bluetooth (e.g., 2.4 GHz), Ultra Wide Band (UWB) (e.g., 3.1˜10.6 GHz) and the like therein. As described above, when a plurality of antennas are mounted to the wireless communication device, the wireless communication device needs large spaces to place the antennas. The plurality of antennas and installation spaces thereof are important contributing factors associated with increases in product price. Accordingly, small sized and plane typed wideband antennas which can accommodate communication systems of various frequency bands through one antenna have been developed.
In consideration of the trend of recent antenna technologies, a next generation mobile communication system may include a plurality of antennas (the integral antenna is also referred to as an “intenna”) within a mobile communication terminal as described above, and an antenna capability reference for minimizing mutual interference between the integral antennas in order to improve quality of a transmitted/received signal becomes more strict. In connection with the above description, installing two or more multi antennas in the mobile communication terminal in order to increase a channel capacity and a signal reliability in 3.5G and 4G systems corresponding to the next generation mobile communication system may be beneficial. Further, in order to mitigate multi-path fading of the mobile communication system, a diversity antenna may be installed in the mobile communication terminal.
According to the related art, wireless communication devices including a plurality of band antenna units include a high frequency antenna unit, a high frequency matching circuit unit, a high frequency band driving circuit unit for processing a high frequency band for each band, a low frequency antenna unit, a low frequency matching circuit unit, and a low frequency band driving circuit unit for processing a low frequency band.
The high frequency antenna unit performs a function of radiating and transmitting a signal suitable for a corresponding high frequency band or receiving a signal, and the high frequency matching circuit unit is connected between the high frequency antenna unit and the high frequency band driving circuit unit to perform an impedance matching function. In addition, the high frequency matching circuit unit matches impedance of the high frequency antenna unit with impedance of the high frequency band driving circuit unit to allow the high frequency antenna unit to maximally receive a radio frequency signal of a desired frequency band. For example, the high frequency matching circuit unit performs impedance matching by using a specific inductor and capacitor, and is generally designed to be suitable for a frequency according to a service provider. The high frequency band driving circuit unit processes various signals transmitted/received in a corresponding high frequency band and is generally implemented in one chip form.
The low frequency antenna unit performs a function of radiating and transmitting a signal suitable for a corresponding low frequency band to the outside or receiving the signal from the outside. The low frequency matching circuit unit is connected between the low frequency antenna unit and the low frequency band driving circuit unit to perform an impedance matching function. The low frequency band driving circuit unit processes various signals transmitted/received in a corresponding low frequency band.
Meanwhile, each of a first antenna unit and a second antenna unit is installed in an upper side of the general wireless communication device including a plurality of antenna units and a third antenna unit is installed in a lower side of the wireless communication device. At this time, the first antenna unit may be a WiFi antenna, the second antenna unit may be a Global Positioning System (GPS) antenna, and the third antenna unit may be a 2G/3G/LTE antenna.
Further, a Near Field Communication (NFC) antenna may be further installed in a back surface of a battery or an internal surface of a battery cover as a fourth antenna unit.
As described above, according to the related art, the general wireless communication device which provides services across a plurality of frequency bands may have a separate antenna unit for each respective frequency band, a separate matching circuit unit, and a separate driving circuit unit for processing suitable for each frequency band. Particularly, an antenna unit which accounts for a significant volume may include an antenna unit having a separate space for each corresponding service (e.g., 3G, LTE, Bluetooth, WiFi, DMB, NFC, and the like). Accordingly, as types of wireless communication services increase and sizes of wireless communication terminals gradually become smaller, an efficient antenna design method for solving the problem associated with narrowing a space in which the antennas are installed is required.
The above information is presented as background information only to assist with an understanding of the present disclosure. No determination has been made, and no assertion is made, as to whether any of the above might be applicable as prior art with regard to the present disclosure.